The lights dim, and a wild-looking man in blonde dreadlocks bounds onto the stage like a gibbon who's had too much caffeine. "I," he announces, "am an endangered species - a 34 year old white man who has decided to emigrate to South Africa ... Everybody else seems to be going the other way."

That's compere Mark Sampson's introduction to an evening of comedy that would leave no rolling room in the aisles of a conventional theatre. Luckily the auditorium at the Armchair in Cape Town is more informally arranged, allowing guests to hurl themselves back into old sofas when the laughter gets too painful.

"Comedy for the People - by the People," is Mark's catchphrase, which he gets sections of the audience to chant competitively at one another.

Mark Sampson comperes comedy shows

The three-hour laughathon he's hosting is organised by the Cape Comedy Collective, a group he founded with his wife, the promoter Sam Pearce. They're dedicated to fostering a new type of edgy, observational humour that breaks down barriers and challenges racial stereotypes.

"I get stopped so often by security guards in Woolworths that my white criminal friends now hire me out as a decoy," jokes one of the black stars of Sam's comedy stable, 22-year-old Kagiso Lediga.

Later in his set he mocks the "don't bite me" smile he says he gets from whites on the street.

You might think such dangerous material would be uncomfortable for the mainly white audience that gathers at the Armchair Theatre. But Sam Pearce says black comics like Kagiso can get away with it if they don't appear too confrontational.

"Kagiso has a certain humility on stage," she says. "He laughs at himself before he laughs at everyone else: he's not a black comedian dissing white people for the sake of it."

Kagiso Lediga satirises prejudice head-on

That approach is even more obvious with some other members of the Cape Comedy Collective's rainbow line-up. Marc Lottering, who's now become well-known on TV, takes his material from the Coloured, or mixed-race, townships where he grew up, on the Cape Flats outside Cape Town.

The townships are best known for their poverty and crime. Most white Capetonians consider them no-go areas. But Marc Lottering's best-known character - a "strangely endearing" elderly Coloured lady called Auntie Merle - is the picture of would-be gentility. She's also an irremediable racist.

"I've got this new black maid - Lydia," says Auntie Merle. "The other day she was sitting on the sofa and I was vacuuming up all around her. What can you do? They answer in full sentences nowadays.

But actually, my maid Lydia and I, we get on like a house on fire. If we didn't, she'd set my house on fire."

"The reason why a character like Auntie Merle works is that she's so honest," Marc Lottering says. "She shows racism to be ridiculous. People recognise her in their own family - everyone knows an Auntie Merle. She's also a typical victim of apartheid."

The Armchair Theatre draws a multiracial audience

Performers like Marc Lottering are breaking the mould of traditional South African humour.
Until recently the scene was dominated by white comedians who stuck mainly to "safe" routines based on stereotypes - sexist, and sometimes racist too.

Writer and critic Marianne Thamm says the new style of humour is badly needed because it releases tensions, allowing sensitive subjects to be approached in an acceptable way. Attitudes that would never be voiced at a dinner party can be safely explored through laughter on stage.

What's not clear is how wide an audience the new comedy is reaching. The Cape Comedy Collective tries hard to find venues in townships and other places where people would probably not have been exposed to alternative humour before.

Nevertheless, the collective is inevitably preaching partly to the converted. Its main base, the Armchair Theatre, is in Observatory, one of the very few areas of Cape Town which is genuinely mixed, and known for its easy-going, liberal values.

Many people claim that in South African society at large, racist attitudes are being expressed increasingly openly again following the initial euphoria - or relief - at the peaceful transition to majority rule.

Riaad Moosa's act sends up stereotypes

Sam Pearce however argues that her collective is making a difference, in a small way, every day, helping to forge one nation out of many separate and mutually suspicious communities.

"In a previous life Riaad and Tracey would never even have met," she says, referring to two of her star turns - a young Muslim medical student and a divorced Jewish mother of three. "Now they're sharing their punchlines and helping one another with their material.

Not only by seeing them together on stage does it create a positive impression - their very working together shows me that people can live in harmony here."

Also in this edition of Crossing Continents: a visit to the new no-frills bank which is offering accounts and loans in the townships and the story of how the AIDS epidemic is leading to more cross-racial adoption.